On Jesus by Doug Groothuis is part of the Wadsworth Philosophers Series – a series of short books, each providing brief and accessible insight into the ideas of major philosophers throughout history. In On Jesus, Doug Groothuis explores the life of Jesus philosophically. Looking at the life and teachings of Jesus through this lens, the author explores the key philosophical categories and paints a powerful picture of Jesus, the philosopher.

The book is ninety-five pages long with eight chapters. Groothuis explains the goal of the book: “On Jesus is not a ‘life of Christ’ or a history of Christianity. […] Rather, it investigates Jesus as a bona fide philosopher, whatever else he may be.”(preface) Chapter one addresses the question head on; Was Jesus a philosopher? Groothuis first discusses what philosophy is, then what a philosopher is, before affirming that Jesus can indeed be seen as a philosopher.

Groothuis anticipates some objections: “Some Christians might even regard the notion that Jesus was a philosopher as ill-advised or blasphemous, since they take him to be God Incarnate. God has no need of human philosophy, after all.”(8) To this he answers, “First, one need not bristle at the thought that even God Incarnate might philosophize with lesser beings, if it were for the purpose of engaging their God-given reasoning abilities.” Moreover, “Second, and more generally, a claim to divine or supernatural inspiration (whether explicit or implicit) need not rule out reasoning and debate in principle.”(9) The author shows that Jesus was a philosopher, and much more.

Chapter two lays some necessary foundations for the whole inquiry, looking at the actual historicity of Jesus as a historical figure. For this, Groothuis argues for the reliability of the New Testament Gospels, their textual transmission, and their relevance to the historical Jesus. He explores the authorship of the Gospels and compares them to other non-biblical sources such as the Gnostic documents. With this foundation, one can explore the life and teachings of Jesus and evaluate how they fit into a philosophical framework.

In chapter three, Groothuis surveys the use of argument by Jesus. Here the author demonstrates that Jesus did not disparage rationality. Rather, Jesus was a master in argument. His use of logic was flawless and his ability to dialogue and dispute with the religious leaders of his day was unparalleled. The author notes Jesus’ frequent appeals to evidence, noting that Jesus was far from being one who promoted unthinking or blind faith over reasoning.

In chapters four through six, the author focuses on three philosophical categories: metaphysics, epistemology, and ethics. For each category (each with its own chapter) Groothuis unpacks Jesus’ view in that area according to his life and teaching. For instance, for Jesus’ metaphysics, the author points out Jesus’ theism, his view of humanity, Jesus’ view of history and the afterlife, and the nature of reality. Jesus’ epistemology uses factual evidence, noncontradiction as a test for truth, and so on. What emerges from a look at the philosophy of Jesus is simply a robust Christian worldview, revealed clearly from the direct teachings of Jesus himself. As the main core of the book has been established, Groothuis contributes another chapter on Jesus’ view of women, showing the value and dignity Jesus gave them.

The author concludes with chapter eight entitled Who Do You Say That I Am? This chapter notes the significance of the question of Jesus’ identity. Here the author also presents arguments for the divinity of Jesus as well as the historicity of Jesus’ resurrection.

“The question of Jesus’ identity, crucifixion, and resurrection is more than a matter of scholarly debate […]. Because Jesus articulated a fully-orbed worldview and often argued for it philosophically, our view of Jesus and his teachings also engenders questions about ourselves, our morality, our place in the cosmos, and the afterlife. But Jesus did not stop there. Through his words and deeds he presented himself – if the documents are to be accepted as factual – as the unique revelator and mediator of the ultimate and sacred reality, the hinge of history, and the portal to eternity.” (95)

In sum, On Jesus is an insightful book, revealing the philosophical bedrock of the Christian worldview, as spelled out through the teachings of Jesus. What is more, it shows that Jesus, as a philosopher, is unlike any other philosopher. The reader is also left with the most important of all questions: “Who do you say that I am?”